rusticleEtymologyBlend of rust + icicle, coined by Robert Ballard, who first observed them on the wreck of the Titanic in 1986.rusticle means An icicle-shaped rust formation, formed on shipwrecks etc. by underwater microbes that consume iron. Lexicurio rates it Rare gem — a strength score of 80 out of 100.nounAn icicle-shaped rust formation, formed on shipwrecks etc. by underwater microbes that consume iron.